The study, conducted over mice, suggests that the health problems associated with disruptions to animals’ 24-hour rhythms of activity and rest — which in humans is linked to eating for most of the day or doing shift work — can be corrected by eating all calories within a 10-hour window.
For many of us, the day begins with a cup of coffee first thing in the morning and ends with a bedtime snack 14 or 15 hours later, said Satchidananda Panda, Professor at the Salk Institute.
But restricting food intake to 10 hours a day, and fasting the rest, can lead to better health, regardless of our biological clock, he added.
The researchers demonstrated that the circadian clocks strikes a balance between sufficient nutrition during the fed state and necessary repair or rejuvenation during fasting.
When this internal clock is disrupted, as when humans do shift work, or when it is compromised due to genetic defects, the balance breaks down and diseases set in.
For the study, which appeared in the journal Cell Metabolism, the team disabled the genes responsible for maintaining the biological clock in mice, including in the liver, which regulates many metabolic functions.
They then put the mice on one of two high-fat diet regimes: one group had access to food around the clock, the other had access to the same number of calories only during a 10-hour window.
As expected, the group that could eat at any time became obese and developed metabolic diseases.
But the group that ate the same number of calories within a 10-hour window remained lean and healthy — despite not having an internal biological clock and thereby genetically programmed to be morbidly sick.
Many of us may have one or more disease-causing defective genes that make us feel helpless and destined to be sick. The finding that a good lifestyle can beat the bad effects of defective genes opens new hope to stay healthy, Panda said.